Aussie Desert Coolers or Ebay. You won't need a 4 row for a 253. Just a 2 row will be fine or 3 row if A/C and towing heaps. You should still be able to buy cores for originals too if you have any radiator shops nearby. Natrad should still have both cores and standard type radiators. You might even pick up a good used one, I still have good HK V8 radiators and HQ 5 row ones that I keep for my cars, but I still get them serviced (tank off and cleaned) prior to use so it still costs $150 or so whereas a new one is about $450+.

Edited by user Wednesday, 24 January 2024 5:55:01 AM(UTC)  | Reason: Not specified

They used to do brass/copper. May have stopped.
Have a look on EBay, plenty of 3 or 4 row in there for around $500 give or take with free delivery.
Try ringing Natrad, they have plenty of outlets in WA.

Also noticed Retro Spares have HQ-HZ 3 row 253/308 for $650.